Study On Mechanical Properties Of Foam Metal/Epoxy Interpenetrating Phase Composites

Foam metal/epoxy interpenetrated phase composites have a wide range of promising applications in aviation,aerospace,transportation,energy and construction.At present,the existing studies on the intrinsic structure relationship of such composites are either too complicated or not accurate enough.The purpose of this paper is to establish a relatively accurate and simple system of intrinsic constitution relationships by combining the tensile and compressive bimodal characteristics of the materials to provide a theoretical basis and reference for material selection and proportional configuration in applications.Firstly,the mechanical properties of the foam-metal/epoxy interpenetrated phase composites in compression were investigated based on the characteristics of the double modulus.A cubic-type fine-scale mechanical representative unit was constructed,and the compressive principal equations for the elastic-plastic deformation were derived in stages using the multiscale method.The analytical solution of the uniaxial compressive stress-strain relationship of the representative unit is derived for the foam Ni-Fe/epoxy interpenetrated phase composites,and the rationality and applicability of the obtained model are verified by quasi-static compression tests on foam Ni-Fe /epoxy interpenetrated phase composites.Secondly,the tensile instantonal equations for the elastic-plastic deformation of the representative unit of the interpenetrating phase of the foam-metal /epoxy composite were developed by the multiscale method,considering the interfacial strength of the matrix phase and the reinforcing phase and the initial damage of the matrix phase for the tensile loading patterns at room temperature and low temperature.The parameters of the tensile instantonal equation were determined by using the peel test of foam Ni-Fe /epoxy composite,the ultimate damage parameters were determined by the fracture toughness test,and the parameters of the instantonal equation were determined by inversion of the uniaxial tensile test results,and the analytical solutions of the stress-strain relationships corresponding to different pore sizes of these composites at room temperature and low temperature were given.Finally,a new type of foam Ni-Fe /epoxy interpenetrated phase composite plate joint is developed and designed for the limitations of cold bridging and weak shear strength of concrete sandwich wall connectors.The test results show that the new connector has lower thermal conductivity and higher shear strength,and the finite element method analysis further reveals its shear deformation mechanism and proposes a method to enhance the shear strength of the connector.The new connectors have significant advantages in mechanical properties such as thermal insulation,ductility and energy absorption compared with commonly used connectors in engineering,which provide the theoretical basis for their application in the construction field or other engineering fields.